This invention relates to an improvement in a hone for sharpening rotary knife blades and more particularly to knife sharpening means for slicing machines of the type embodying non-circular or involute rotary knives whereby the knives may be sharpened in situ without necessitating removal thereof from the slicing machine. The sharpening apparatus which has been illustrated herein is in the form of an attachment for existing slicing machines, but may by suitable modification be designed as original equipment on a slicing machine as manufactured.
Raine U.S. Pat. No. 2,978,848 discloses a grinder for sharpening an involute knife. The grinding wheel is positioned on the knife edge by means of a guide block, which rides on one of the beveled knife edge surfaces. However, as a practical matter, because of the geometry of the vertical movement of the guide block, the grinding wheel only approximately follows a portion of the knife edge. The result is that the entire knife edge is not satisfactorily sharpened.
Goode U.S. Pat. No. 3,820,289 sets forth the disadvantages of the device of the Raine U.S. Pat. No. 2,978,848 and points out how it is an improvement. However, the Goode grinder assembly is mounted on an arm which has a yoke at its lower end to which are bolted fingers. The yoke fingers engage the shaft of the knife shaft. The yoke and fingers are guided by the knife shaft to adjust the angle of the arm on which the assembly is mounted with respect to the radius of said shaft. The assembly of the present invention eliminates the necessity for the yoke and fingers of Goode and is an improvement over the apparatus of that patent.
Other patents, such as those cited in the Raine and Goode patents, disclose devices for sharpening circular knives, but none show the assembly of the present invention.